Building management systems monitor and control several systems in a building such as heating, air-condition, lighting, mechanical systems and various other kinds of alarms. To be able to manage the building in an automatic way the building management system collects data from many sensors installed throughout the building.
Conventional building management systems make in general use of the “cloud” for storage, where management services can be booked on demand. Therefore conventionally building data is kept outside the building and even outside the building management organization at a cloud storage or cloud service providers.
However, this causes several problems, in particular security and privacy problems: When the data is collected this data is strongly correlated with actions of persons leading to severe privacy issues in residential buildings. Also in office environments data which is collected from the sensors in the building may reveal personal preferences and habits of employees. Even further the collected data may allow deriving confidential information of a company, for example the work load of groups and departments.
Further a security problem arises when the data is initially collected as a whole and later a focus on the relevant subset of the data is set being a source of threats, in particular when considering outsourcing of data analysis to third parties.